\brief \b ESMF_DLAEDA used by sstedc. Computes the Z vector determining the rank-one modification of the diagonal matrix. Used when the original matrix is dense. \htmlonly Download ESMF_DLAEDA + dependencies [TGZ] [ZIP] [TXT] \endhtmlonly \par Purpose:
\verbatim
ESMF_DLAEDA computes the Z vector corresponding to the merge step in the CURLVLth step of the merge process with TLVLS steps for the CURPBMth problem. \endverbatim \param[in] N \verbatim N is INTEGER The dimension of the symmetric tridiagonal matrix. N >= 0. \endverbatim
\param[in] TLVLS \verbatim TLVLS is INTEGER The total number of merging levels in the overall divide and conquer tree. \endverbatim
\param[in] CURLVL \verbatim CURLVL is INTEGER The current level in the overall merge routine, 0 <= curlvl <= tlvls. \endverbatim
\param[in] CURPBM \verbatim CURPBM is INTEGER The current problem in the current level in the overall merge routine (counting from upper left to lower right). \endverbatim
\param[in] PRMPTR \verbatim PRMPTR is INTEGER array, dimension (N lg N) Contains a list of pointers which indicate where in PERM a level’s permutation is stored. PRMPTR(i+1) - PRMPTR(i) indicates the size of the permutation and incidentally the size of the full, non-deflated problem. \endverbatim
\param[in] PERM \verbatim PERM is INTEGER array, dimension (N lg N) Contains the permutations (from deflation and sorting) to be applied to each eigenblock. \endverbatim
\param[in] GIVPTR \verbatim GIVPTR is INTEGER array, dimension (N lg N) Contains a list of pointers which indicate where in GIVCOL a level’s Givens rotations are stored. GIVPTR(i+1) - GIVPTR(i) indicates the number of Givens rotations. \endverbatim
\param[in] GIVCOL \verbatim GIVCOL is INTEGER array, dimension (2, N lg N) Each pair of numbers indicates a pair of columns to take place in a Givens rotation. \endverbatim
\param[in] GIVNUM \verbatim GIVNUM is DOUBLE PRECISION array, dimension (2, N lg N) Each number indicates the S value to be used in the corresponding Givens rotation. \endverbatim
\param[in] Q \verbatim Q is DOUBLE PRECISION array, dimension (N**2) Contains the square eigenblocks from previous levels, the starting positions for blocks are given by QPTR. \endverbatim
\param[in] QPTR \verbatim QPTR is INTEGER array, dimension (N+2) Contains a list of pointers which indicate where in Q an eigenblock is stored. SQRT( QPTR(i+1) - QPTR(i) ) indicates the size of the block. \endverbatim
\param[out] Z \verbatim Z is DOUBLE PRECISION array, dimension (N) On output this vector contains the updating vector (the last row of the first sub-eigenvector matrix and the first row of the second sub-eigenvector matrix). \endverbatim
\param[out] ZTEMP \verbatim ZTEMP is DOUBLE PRECISION array, dimension (N) \endverbatim
\param[out] INFO \verbatim INFO is INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. \endverbatim \author Univ. of Tennessee \author Univ. of California Berkeley \author Univ. of Colorado Denver \author NAG Ltd. \date December 2016 \ingroup auxOTHERcomputational \par Contributors:
Jeff Rutter, Computer Science Division, University of California at Berkeley, USA
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer | :: | N | ||||
| integer | :: | TLVLS | ||||
| integer | :: | CURLVL | ||||
| integer | :: | CURPBM | ||||
| integer | :: | PRMPTR(*) | ||||
| integer | :: | PERM(*) | ||||
| integer | :: | GIVPTR(*) | ||||
| integer | :: | GIVCOL(2,*) | ||||
| double precision | :: | GIVNUM(2,*) | ||||
| double precision | :: | Q(*) | ||||
| integer | :: | QPTR(*) | ||||
| double precision | :: | Z(*) | ||||
| double precision | :: | ZTEMP(*) | ||||
| integer | :: | INFO |